Congenital intracranial cysts: clinical findings, diagnosis, treatment and follow-up. A multicenter, retrospective long-term evaluation of 72 children

Peripetrosal arachnoid cysts

PURPOSE OF REVIEW

The present review summarizes the current theories on arachnoid cyst formation, the common presentations of cysts surrounding or eroding the temporal bone from the middle and posterior cranial fossae, the diagnostic strategies and the management considerations and options.

RECENT FINDINGS

Arachnoid cysts are most common in the middle cranial fossa and rarely present in association with the petrous apex. They are frequently found incidentally on imaging studies performed in the workup for unrelated symptoms. When they do cause symptoms, these are usually nonspecific. Thus it is important to establish the relationship between the two. Peripetrosal arachnoid cysts may cause cranial nerve deficits in addition to symptoms related to intracranial hypertension. Small asymptomatic cysts are managed conservatively with serial imaging. Large symptomatic cysts are often managed surgically with shunting, open excision or open or neuroendoscopic fenestration or marsupialization. The management of large asymptomatic cysts depends on the patient and cyst characteristics.

SUMMARY

Peripetrosal arachnoid cysts are often incidental findings. Careful selection of surgical candidates is of utmost importance. Multiple surgical options with similar success rates are available. The rates and profile of their complications may differ. Overall, approximately 70% of patients experience improvement in their symptoms with surgery.

Middle cranial fossa arachnoid cysts causing sensorineural hearing loss

Arachnoid cyst of the middle cranial fossa has never been reported to present with sensorineural hearing impairment. We report the case of a 15-year-old girl who complained of progressive hearing loss on the right side for 4 years. The pure tone audiometry revealed sensorineural hearing loss with an average of 63 dB, and the auditory brain stem response demonstrated absence of all waves on the right side. Magnetic resonance imaging showed giant arachnoid cysts occupying the bilateral middle cranial fossa and extending to the parietal and prepontine areas with the atrophic change of the right facial-acoustic nerve cord and a decrease in signal intensity of the right cochlea and vestibule. The cystoperitoneal shunting procedure was suggested, but the parents hesitated about the surgical treatment. The patient has not received any surgical intervention, and her hearing has been stable for 1 year during the follow-up period. This case represents the first report that sensorineural hearing loss is a possible presenting symptom when arachnoid cysts of the middle cranial fossa are massive.

Endoscopic ventriculo-cystomy for non-communicating hydrocephalus secondary to quadrigeminal cistern arachnoid cyst

INTRODUCTION

Intracranial arachnoid cysts are developmental, anomalous collections of cerebrospinal fluid (CSF), and occasionally cause symptoms when large enough to obliterate the CSF outflow pathway and give rise to non-communicating hydrocephalus. The treatment of choice for symptomatic arachnoid cysts has been surgical excision or fenestration of the cyst, but less invasive endoscopic fenestration has been attempted with favorable preliminary results.

CASE REPORT

We report a case of non-communicating hydrocephalus caused by a quadrigeminal cistern arachnoid cyst in a 35-year-old woman who presented with worsening headaches. She was successfully treated by endoscopic third ventriculostomy and fenestration of the cyst (ventriculo-cistomy).

DISCUSSION

Endoscopic fenestration of symptomatic arachnoid cysts can be as effective as open surgery in terms of short-term efficacy, and it is certainly less invasive than open surgery. However, its long-term outcome remains unknown, and these rare cases require careful clinical and radiological follow-up.

First-trimester diagnosis of fetal arachnoid cyst: prenatal implication

We report a case of the early diagnosis of an arachnoid cyst. Transvaginal ultrasound examination of the fetal brain at 13 weeks' gestation revealed the presence of an anechoic mass above the posterior fossa. After extensive counseling and because of the uncertain prognosis of a first-trimester diagnosis of an arachnoid cyst, the parents opted for termination of pregnancy. The diagnosis was confirmed by postmortem examination.

Massive intracranial arachnoid cyst in a developmentally normal infant: case report and literature review

Intracranial arachnoid cysts are developmental anomalies that are generally asymptomatic. We describe a 6-month-old boy with macrocephaly but normal neurological development who was found to have a rare, massive basal arachnoid cyst occupying most of the cranium and extending superiorly, causing significant shift due to mass effect. A cystoperitoneal shunt was placed, producing both a decrease in the arachnoid cyst dimensions and a concomitant reexpansion of parenchyma. After consideration of various management options, such a shunt system appears to offer a low risk of complications and a high likelihood of success.

Dandy-Walker syndrome presenting as opisthotonus: proposed pathophysiology

A patient with radiographically confirmed Dandy-Walker syndrome who presented with opisthotonus, a rarely reported clinical manifestation, is reported. From four separate pharmacologic trials (baclofen, diazepam, levodopa/carbidopa, and trihexyphenidyl), combination baclofen and diazepam therapy was determined to be most efficacious. Opisthotonus and extensor posturing remain only rudimentarily understood. We review the subject and propose a specific mechanism relating our patient's anatomic and physiologic conditions.